USS San Diego-- Part 4: Court of Inquiry Determines It Was a Mine

In August, the Navy Court if Inquiry appointed to investigate the loss of the cruiser concluded that the San Diego had been sunk by a mine..  Part of this was based on the fact that six contact mines had been found in the vicinity of where it sank.

The German submarine U-156 had earlier laid a number of mines along the south shore of Long Island and the sinking of the San Diego was attributed to her.

In 1999, a theory was advanced that a German spy by the name of Kurt Jahnke had planted explosives aboard the San Diego and caused its sinking.  This claim has been contested by the Naval Historical Center.

--Cooter